CircRNA cPWWP2A: an emerging player in diabetes mellitus.

Circular RNAs(CircRNAs), a new class of non-coding RNAs, possess significant capabilities of gene regulation and are disrupted in various diseases, including diabetes mellitus (DM). However, the underlying mechanism of CircRNAs in DM and diabetic complications remains illusive. A recent study published by Liu et al. (Proc Natl Acad Sci USA 116:7455-7464, 2019) shown that a novel diabetic retinopathy (DR)-associated CircRNA cPWWP2A, which could act as a competing endogenous RNA interacting with miR-579 to promote the DR-induced retinal vascular dysfunction through up-regulating the expression of Angiopoietin 1, Occludin, and SIRT1. Their findings may provide new insight into the potential use of CircRNA cPWWP2A for the targeted therapy of DR. However, those promising findings may need to be further evaluated detailedly for the following reason. (1) This study doesn't well clarify why the most significantly up-regulated CircRNA mmu _circ_0000254 the fold change of which is 160.581 is excluded,while the cPWWP2A the fold change of which is only 3.487 is chosen. (2) It is difficult to conclude that cPWWP2A competing with miR-579 only by the analysis of colocalization in pericytes.